This invention is directed to engines and more particularly to improving fluid flow into and exhaust flow out of the engine cylinders.
It is known that as the air-fuel mass flowing through the intake port of a modern engine encounters the valve head, it is naturally formed into a path around the head. The flow dynamics, created when the rushing gaseous mass encounters the relatively large valve head and is pulled away from the valve stem, well above the valve head, and forces the gaseous mass to form a substantially cone-shaped umbrella around the valve head. Adjacent to the valve stem there is no flow whatsoever. The entire flow path is adjacent to the edge of the valve head.
As the gaseous mass moves past the rim of the valve, and flows into the cylinder it forms another cone downstream of the valve head.
Because of this phenomenon, it has been long known that the length of the gasious mass cone extending into the cylinder is of extremely short duration and accordingly must not be disturbed in any way. Maximum flow is achieved by undisturbed cone action below the valve head.
It is also well known that intake valve design contributes to the flow of the gasious mass into the cylinders. An ideal intake seat and valve face are shown in FIG. 1. The seats and faces must be concentric with a measured runout less of than 0.001 inch. The valve faces should terminate right on the very outer edge of the facing surface. The edges where the lead-in and top cuts meet the face or seat cuts must not be radiused. These edges should be sharply defined, for absolute maximum performance. Referring to the prior art shown in FIG. 1, the intake port A, cylinder head intake port B, intake valve C and combustion chamber D are shown. At location E a 60 degree bottom cut is made. At location F a 45 degree seat in the range of 0.030-0.060 inches is formed. At location G a 15 degree top cut is made. A radius is formed at location H which extends from the topcut to the margin. A 35 degree under cut is made on the edge of the underside of the valve C at location I. A 45 degree face edge is formed on the planar valve face at location J. The end margin or edge width of the valve at location L should be between 0.030-0.050 inches. The dimension of the valve stem M should be as small as physically allowable for valve stem operating integrity. A valve rim or margin width is taught to be no greater than 0.050 inches. With any increase from this maximum thickness believed to provide no improvement to gas flow while adding undesirable mass to the valve head.
It is apparently unknown in the present state of the art that in fact the ideal desired conic gas flow shape beneath the valve head along the cylinder walls extends only a short distance into the cylinder past the valve face and then almost immediately expands toward the center of the cylinder while gas on the inside of the cone adjacent to the margin clings to the valve edge surface and follows the topcut to the valve face surface creating eddies which produce undesirable turbulence along the valve face. This turbulence causes uneven distribution of gas within the cylinder resulting in inefficient combustion.
Ideally, the cone should extent well into the cylinder approaching the bottom thereof. The present intake valve configuration is directed to reducing the eddies and the resulting turbulence normally created along the valve face by extending the cone to a greater depth within the cylinder thereby producing a more efficient and cleaner burning of the combustible gas delivered to the cylinder.
An ideal exhaust valve is shown in FIG. 2 also identified as prior art. As can be seen in FIG. 2, the exhaust port M is similar to the intake port A except that the bottom cut E is replaced with a curvilinear wall N. The other elements remain substantially the same including the planar valve face. The exhaust valve is similar to the intake valve except that the under cut is eliminated and the margin is increased to a range of from 0.030-0.060 inches. The top cut L is maintained.
The gas flow from the cylinder during the exhaust cycle is similar to the intake gas flow except that the spent gas flows in the opposite direction. A similar cone of exhaust gas is formed as the exhaust gas passes around the valve edge and through the exhaust port between the margin and valve seat. Any turbulence to this gas flow decreases the efficiency of exhaust gas removal and results in engine inefficiency.
The prior art ideal exhaust valve has drawbacks that have been substantially overcome by this invention. The rectilinear bottom cut causes the exhaust gas flow to break away from the valve face at the topcut and margin joinder which creates eddies and resulting turbulence in the cone of exhaust gas passing between the valve seat and margin. The addition of a Coanda effect curvilinear edge between the valve face and margin, and the increased margin dimension, Feuling effect, of the present invention causes the exhaust gas to adhere and substantially follow the valve rim between the valve face and margin rather than break away therefrom as with the supposed ideal exhaust valve configuration. Turbulence and the resulting inefficient flow is thereby substantially eliminated providing an increase in engine efficiency.
There has not been any use of an extended margin for intake valves of an internal combustion engine used in combination with the Coanda effect between the bottom and margin of the valve or in exhausted valves the combination of the extended margin and Coanda effect between the bottom of the valve and the margin and between the face of the valve and margin until the emergence of this invention.